1. Technical Field
The present invention relates to a two-wheeled mobile robot system and its motion control method which can provide an experimental research platform for control theory courses and robot design courses in engineering and polytechnic colleges and universities.
2. Description of Related Art
The two-wheeled self-balancing robot is also known as a “mobile inverted pendulum”. Its locomotion mechanism is the two wheels connected on both sides of the body in parallel whose axle centers face each other. This robot has both the problem of discrete time action decision for a mobile robot and the problem of continuous time attitude control for an inverted pendulum. Therefore, it can be an integrated cross research object and an ideal teaching demonstration device in the fields of robotics and control science.
The entire body of the existing two-wheeled self-balancing robot is of rigid construction, such as the robot disclosed in Patent ZL200510094939.X. From the view that the robot is designed by simulating human body, the rigid structure is unable to reflect the human body, especially the flexibility (elasticity) of the waist structure in the back-forth pitching motion. However, a robot that completely imitates the human body and designed by means of artificial muscles and artificial joint soft tissues is difficult to realize, high in cost, complicated to control and difficult to maintain, so it is impractical to take it as the research on balancing control and motion control problem and teaching demonstration device of flexible body robot.
To aim at addressing the abovementioned problems, Patent ZL200720103279.1 designs a flexible two-wheeled upright robot body. The robot introduces a cylindrical spring connection to realize flexible body. This design is simple and easy to realize, but there are still some deficiencies: first, a simple cylindrical spring connection mode enables the flexible segment of the robot to have unlimited freedom, wherein most parts are not controllable, such as the freedom of left-right sway, which has no prominent significance for the research of attitude control two-wheeled upright robot, but brings about more unnecessary troubles; second, with the height of the elastic joint unchanged, the change of diameter in the cylindrical spring material and cycles is limited, directly restricting the value taking scope of rigid value of the elastic joint, thus the robot is deficient on maneuverability and parameters adjusting scope as a teaching demonstration device. In addition, Patent ZL200720103279.1 relates to the mechanical body structure of such robot only, not the electric system as applied to the robot and attitude balancing control method.